Submission #697652

#	Time	Username	Problem	Language	Result	Execution time	Memory
697652		tamthegod	Senior Postmen (BOI14_postmen)	C++17	100 / 100	397 ms	51496 KiB

postmen

// Make the best become better
// No room for laziness
#include<bits/stdc++.h>

#define pb push_back
#define fi first
#define se second
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 5e5 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e18;
int n, m;
int id = 0;
vector<int> path;
vector<int> adj[maxN];
struct TEdge
{
    int u, v;
    bool del;
} e[maxN];
void ReadInput()
{
    cin >> n >> m;
    for(int i=1; i<=m; i++)
    {
        int u, v;
        cin >> u >> v;
        e[i] = {u, v, 0};
        adj[u].pb(i);
        adj[v].pb(i);
    }
}

void FindEulerTour()
{
    vector<int> vc;
    vc.pb(1);
    while(!vc.empty())
    {
        int u = vc.back();
        while(!adj[u].empty() && e[adj[u].back()].del) adj[u].pop_back();
        if(!adj[u].empty())
        {
            int id = adj[u].back();
            adj[u].pop_back();
            e[id].del = 1;
            vc.pb(e[id].u ^ e[id].v ^ u);
        }
        else
        {
            path.pb(u);
            vc.pop_back();
        }
    }
}
int vis[maxN];
void Solve()
{
    FindEulerTour();
    int tmp = 0;
    vector<int> bin;
    for(int u : path)
    {
        if(vis[u])
        {
            while(true)
            {
                int v = bin.back();
                bin.pop_back();
                cout << v << " ";
                vis[v] = 0;
                if(v == u) break;
            }
            cout << '\n';
        }
        vis[u] = 1;
        bin.pb(u);
    }
}
int32_t main()
{
    //  freopen("x.inp", "r", stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ReadInput();
    Solve();
}

Compilation message (stderr)

postmen.cpp: In function 'void Solve()':
postmen.cpp:64:9: warning: unused variable 'tmp' [-Wunused-variable]
   64 |     int tmp = 0;
      |         ^~~

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 45 / 45